I thought of something that I might try: for a month, I'll pay for a music subscription service, and just preview a ton of music. This way I can filter out the stuff that I don't like, and only buy the good stuff. This could have saved me from such travesties as Jewel's Pieces of You.
The problem with this plan is that I have liked an overwhelming majority of the music I've purchased in the past few years so I'd end up buying it anyway after rushing to download and listen to as much as I could in a month. I guess, in theory, if it saves me from buying one crappy CD it would be worth it financially, but it might also kind of ruin the experience to listen to have my first impressions of so many CDs be in 128 kbps and only for a relatively short period of time until I pass judgment.